Assuming default behaviour ('no_subtree_check').

nfs服务状态显示Assuming default behaviour ('no_subtree_check').

# /etc/init.d/nfs-kernel-server status
● nfs-server.service - NFS server and services
   Loaded: loaded (/lib/systemd/system/nfs-server.service; enabled; vendor preset: enabled)
   Active: active (exited) since 三 2019-11-06 11:34:42 CST; 5s ago
  Process: 27515 ExecStopPost=/usr/sbin/exportfs -f (code=exited, status=0/SUCCESS)
  Process: 27511 ExecStopPost=/usr/sbin/exportfs -au (code=exited, status=0/SUCCESS)
  Process: 27506 ExecStop=/usr/sbin/rpc.nfsd 0 (code=exited, status=0/SUCCESS)
  Process: 27528 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
  Process: 27525 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=0/SUCCESS)
 Main PID: 27528 (code=exited, status=0/SUCCESS)

11月 06 11:34:42 lthpc exportfs[27525]: exportfs: /etc/exports [2]: Neither 'sub...".
11月 06 11:34:42 lthpc exportfs[27525]:   Assuming default behaviour ('no_subtre...).
11月 06 11:34:42 lthpc exportfs[27525]:   NOTE: this default has changed since n....x
11月 06 11:34:42 lthpc exportfs[27525]: exportfs: /etc/exports [3]: Neither 'sub...".
11月 06 11:34:42 lthpc exportfs[27525]:   Assuming default behaviour ('no_subtre...).

修复办法
在填写/etc/exports 文件时需要填写一个重要参数 no_subtree_check

# cat /etc/exports
# /etc/exports: the access control list for filesystems which may be exported
#       to NFS clients.  See exports(5).
#
# Example for NFSv2 and NFSv3:
# /srv/homes       hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)
#
# Example for NFSv4:
# /srv/nfs4        gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)
# /srv/nfs4/homes  gss/krb5i(rw,sync,no_subtree_check)
#
/WORK5          *(rw,sync,no_subtree_check,no_root_squash)

重启nfs服务，查看状态
/etc/init.d/nfs-kernel-server restart

# /etc/init.d/nfs-kernel-server restart
# /etc/init.d/nfs-kernel-server status
 nfs-server.service - NFS server and services
ervice - NFS server and services
   Loaded: loaded (/lib/systemd/system/nfs-server.service; enabled; vendor preset: enabled)
   Active: active (exited) since 三 2019-11-06 11:37:49 CST; 23min ago
  Process: 27613 ExecStopPost=/usr/sbin/exportfs -f (code=exited, status=0/SUCCESS)
  Process: 27609 ExecStopPost=/usr/sbin/exportfs -au (code=exited, status=0/SUCCESS)
  Process: 27606 ExecStop=/usr/sbin/rpc.nfsd 0 (code=exited, status=0/SUCCESS)
  Process: 27626 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
  Process: 27623 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=0/SUCCESS)
 Main PID: 27626 (code=exited, status=0/SUCCESS)

11月 06 11:37:49 lthpc systemd[1]: Starting NFS server and services...
11月 06 11:37:49 lthpc systemd[1]: Started NFS server and services.